Composition for forming organic film, substrate for manufacturing semiconductor device, method for forming organic film, patterning process, and polymer

Abstract

A composition for forming an organic film contains a polymer having a partial structure shown by the following general formula (1) as a repeating unit, and an organic solvent. Each of AR1 and AR2 represents a benzene ring or naphthalene ring which optionally have a substituent; W1 represents a particular partial structure having a triple bond, and the polymer optionally contains two or more kinds of W1; and W2 represents a divalent organic group having 6 to 80 carbon atoms and at least one aromatic ring. This invention provides: a polymer curable even under film formation conditions in an inert gas and capable of forming an organic film which has not only excellent heat resistance and properties of filling and planarizing a pattern formed in a substrate, but also favorable film formability onto a substrate with less sublimation product; and a composition for forming an organic film, containing the polymer.

The invention claimed is: 
     
       1. A composition for forming an organic film, comprising:
 a polymer having a partial structure shown by the following general formula (1) as a repeating unit; and 
 an organic solvent, 
 
       
         
           
           
               
               
           
         
         wherein each of AR1 and AR2 represents a benzene ring or a naphthalene ring which optionally have a substituent; W 1  represents any shown by the following general formulae (2), (4), and (6), and the polymer optionally contains two or more kinds of W 1 ; and W 2  represents a divalent organic group having 6 to 80 carbon atoms and at least one or more aromatic rings, 
       
       
         
           
           
               
               
           
         
         wherein AR3, AR4, and AR5 each represent a benzene ring or a naphthalene ring which optionally have a substituent, and aromatic rings of AR3 and AR4, or AR4 and AR5, optionally form a bridge structure via carbon atoms to which hydrogen atoms have been bonded on the aromatic ring; and Y represents a substituent shown by the following general formula (3),
   Y═—R 3 ≡R 4   (3)
 
 
         wherein R 3  represents a single bond or a divalent organic group having 20 or fewer carbon atoms; and R 4  represents hydrogen or a monovalent organic group having 20 or fewer carbon atoms, 
       
       
         
           
           
               
               
           
         
         wherein AR 6  and AR 7  each represent a benzene ring or a naphthalene ring which optionally have a substituent; n1 represents 0 or 1, when n1=0, AR 6  and AR 7  form no bridge structure between aromatic rings thereof via Z, and when n1=1, AR 6  and AR 7  form a bridge structure via Z; Z represents a single bond or any in the following general formula (5); and Y represents a substituent shown by the general formula (3), 
       
       
         
           
           
               
               
           
         
         wherein AR 8  represents a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, or a pyrene ring; Y represents a substituent shown by the general formula (3); and n2 and n3 represent integers satisfying relations of 0≤n2≤4, 0≤n3≤4, and 1≤n2+n3≤4. 
       
     
     
       2. The composition for forming an organic film according to  claim 1 , wherein the divalent organic group represented by W 2  in the general formula (1) is any of the following, 
       
         
           
           
               
               
           
         
       
     
     
       3. The composition for forming an organic film according to  claim 1 , wherein the polymer has a weight-average molecular weight of 1000 to 5000. 
     
     
       4. The composition for forming an organic film according to  claim 1 , wherein the organic solvent is a mixture of one or more organic solvents each having a boiling point of lower than 180° C. and one or more organic solvents each having a boiling point of 180° C. or higher. 
     
     
       5. The composition for forming an organic film according to  claim 1 , further comprising at least one of a surfactant and a plasticizer. 
     
     
       6. A substrate for manufacturing a semiconductor device, comprising an organic film on the substrate, the organic film being formed by curing the composition for forming an organic film according to  claim 1 . 
     
     
       7. A method for forming an organic film employed in a semiconductor device manufacturing process, the method comprising the steps of:
 spin-coating a substrate to be processed with the composition for forming an organic film according to  claim 1 ; and 
 heating the substrate to be processed coated with the composition for forming an organic film under an inert gas atmosphere at a temperature of 50° C. or higher and 600° C. or lower within a range of 10 seconds to 7200 seconds to obtain a cured film. 
 
     
     
       8. The method for forming an organic film according to  claim 7 , wherein the inert gas has an oxygen concentration of 1% or less. 
     
     
       9. The method for forming an organic film according to  claim 7 , wherein the substrate to be processed has a structure or step with a height of 30 nm or more. 
     
     
       10. A method for forming an organic film employed in a semiconductor device manufacturing process, the method comprising the steps of:
 spin-coating a substrate to be processed with the composition for forming an organic film according to  claim 1 ; 
 heating the substrate to be processed coated with the composition for forming an organic film in air at a temperature of 50° C. or higher and 250° C. or lower within a range of 5 seconds to 600 seconds to form a coating film; and 
 heating the resultant under an inert gas atmosphere at a temperature of 200° C. or higher and 600° C. or lower within a range of 10 seconds to 7200 seconds to obtain a cured film. 
 
     
     
       11. A patterning process comprising the steps of:
 forming an organic film by using the composition for forming an organic film according to  claim 1  on a body to be processed; 
 forming a silicon-containing resist middle layer film by using a silicon-containing resist middle layer film material on the organic film; 
 forming a resist upper layer film by using a photoresist composition on the silicon-containing resist middle layer film; 
 forming a circuit pattern in the resist upper layer film; 
 transferring the pattern to the silicon-containing resist middle layer film by etching using the resist upper layer film having the formed circuit pattern as a mask; 
 transferring the pattern to the organic film by etching using the silicon-containing resist middle layer film having the transferred pattern as a mask; and 
 etching the body to be processed using the organic film having the transferred pattern as a mask to form the pattern in the body to be processed. 
 
     
     
       12. The patterning process according to  claim 11 , wherein the circuit pattern is formed in the resist upper layer film by a photolithography with a wavelength of 10 nm or more and 300 nm or less, direct lithography with electron beam, nanoimprinting, or a combination thereof. 
     
     
       13. The patterning process according to  claim 11 , wherein alkali development or organic solvent development is employed as a development method. 
     
     
       14. The patterning process according to  claim 11 , wherein the body to be processed is a semiconductor device substrate or the semiconductor device substrate coated with any of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxycarbide film, and a metal oxynitride film. 
     
     
       15. The patterning process according to  claim 14 , wherein the metal is silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, cobalt, manganese, molybdenum, or an alloy thereof. 
     
     
       16. A patterning process comprising the steps of:
 forming an organic film by using the composition for forming an organic film according to  claim 1  on a body to be processed; 
 forming a silicon-containing resist middle layer film by using a silicon-containing resist middle layer film material on the organic film; 
 forming an organic antireflective coating (BARC) on the silicon-containing resist middle layer film; 
 forming a resist upper layer film by using a photoresist composition on the BARC; 
 forming a circuit pattern in the resist upper layer film; 
 successively transferring the pattern by etching to the BARC and the silicon-containing resist middle layer film using the resist upper layer film having the formed circuit pattern as a mask; 
 transferring the pattern to the organic film by etching using the silicon-containing resist middle layer film having the transferred pattern as a mask; and 
 etching the body to be processed using the organic film having the transferred pattern as a mask to form the pattern in the body to be processed. 
 
     
     
       17. A patterning process comprising the steps of:
 forming an organic film by using the composition for forming an organic film according to  claim 1  on a body to be processed; 
 forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a titanium oxide film, and a titanium nitride film on the organic film; 
 forming a resist upper layer film by using a photoresist composition on the inorganic hard mask; 
 forming a circuit pattern in the resist upper layer film; 
 transferring the pattern to the inorganic hard mask by etching using the resist upper layer film having the formed circuit pattern as a mask; 
 transferring the pattern to the organic film by etching using the inorganic hard mask having the formed pattern as a mask; and 
 etching the body to be processed using the organic film having the formed pattern as a mask to form the pattern in the body to be processed. 
 
     
     
       18. The patterning process according to  claim 17 , wherein the inorganic hard mask is formed by a CVD method or an ALD method. 
     
     
       19. A patterning process comprising the steps of:
 forming an organic film by using the composition for forming an organic film according to  claim 1  on a body to be processed; 
 forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a titanium oxide film, and a titanium nitride film on the organic film; 
 forming a BARC on the inorganic hard mask; 
 forming a resist upper layer film by using a photoresist composition on the BARC; 
 forming a circuit pattern in the resist upper layer film; 
 successively transferring the pattern to the BARC and the inorganic hard mask by etching using the resist upper layer film having the formed circuit pattern as a mask; 
 transferring the pattern to the organic film by etching using the inorganic hard mask having the formed pattern as a mask; and 
 etching the body to be processed using the organic film having the formed pattern as a mask to form the pattern in the body to be processed. 
 
     
     
       20. A polymer comprising a partial structure shown by the following general formula (1) as a repeating unit, 
       
         
           
           
               
               
           
         
         wherein each of AR1 and AR2 represents a benzene ring or a naphthalene ring which optionally have a substituent; W 1  represents any shown by the following general formulae (2), (4), and (6), and the polymer optionally contains two or more kinds of W 1 ; and W 2  represents a divalent organic group having 6 to 80 carbon atoms and at least one or more aromatic rings, 
       
       
         
           
           
               
               
           
         
         wherein AR3, AR4, and AR5 each represent a benzene ring or a naphthalene ring which optionally have a substituent, and aromatic rings of AR3 and AR4, or AR4 and AR5, optionally form a bridge structure via carbon atoms to which hydrogen atoms have been bonded on the aromatic ring; and Y represents a substituent shown by the following general formula (3),
   Y═—R 3 ≡R 4   (3)
 
 
         wherein R 3  represents a single bond or a divalent organic group having 20 or fewer carbon atoms; and R 4  represents hydrogen or a monovalent organic group having 20 or fewer carbon atoms, 
       
       
         
           
           
               
               
           
         
         wherein AR 6  and AR 7  each represent a benzene ring or a naphthalene ring which optionally have a substituent; n1 represents 0 or 1, when n1=0, AR 6  and AR 7  form no bridge structure between aromatic rings thereof via Z, and when n1=1, AR 6  and AR 7  form a bridge structure via Z; Z represents a single bond or any in the following general formula (5); and Y represents a substituent shown by the general formula (3), 
       
       
         
           
           
               
               
           
         
         wherein AR 8  represents a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, or a pyrene ring; Y represents a substituent shown by the general formula (3); and n2 and n3 represent integers satisfying relations of 0≤n2≤4, 0≤n3≤4, and 1≤n2+n3≤4. 
       
     
     
       21. The polymer according to  claim 20 , wherein the divalent organic group represented by W 2  in the general formula (1) is any of the following,